1. Field of the Invention.
The invention generally relates to automatic flotation devices, and more particularly to devices which inflate after being submerged in water.
2. Description of the Prior Art.
People have an affinity for the seashore or lakefront so that they can enjoy the environment and go swimming for recreational purposes. However, this enjoyment can be dramatically diminished if the people have to spend great amounts of time preventing possible accidents. For example, if an entire family goes to the beach and that family includes small children who are not skilled swimmers, then the parents have to expend a great amount of effort watching the children to make sure they are not harmed or possibly drowned. This concentration diminishes the enjoyment of the trip for the parents and increases their stress levels.
Certain approaches to resolve this safety problem have been developed in the past, but these approaches are generally relatively uncomfortable or impede mobility of the swimmer. Examples include the use of conventional life vests and, in the case of small children, the use of inflatable arm bands. All of these devices generally limit the mobility of the swimmer so that complete freedom cannot be enjoyed. Therefore, the devices are often not worn by older children who have developed some skill at swimming but are not sufficiently proficient at all levels and in many cases may have momentary lapses in capabilities or panic in emergency situations.
Further, even an experienced swimmer may have difficulty in certain water conditions, for example when a very strong undertow exists. Therefore even for extremely experienced swimmers there is a possibility that they could be submerged for too great a period of time and drown.
There are a number of examples where devices inflate upon sensing the presence of any water. The classic example is an inflatable emergency raft which upon being thrown into the water, immediately or after a short time delay, opens a compressed gas cartridge to cause the raft to automatically inflate. That way the escaping parties need not bother with the problem of trying to find a pin or other inflation trigger. Some of the devices have incorporated a time delay so that they do not open immediately upon entering the water but wait a period of time to make sure that the water truly is present and it is appropriate to inflate. These devices are not appropriate for use with a swimmer because then the swimmer could not even enter the water without the device inflating. This type of device might be appropriate for protecting a child who is not allowed to enter the water, but is not be appropriate for a swimmer who desires to enter the water and perform some activities. Thus, devices which inflate upon mere entry into the water are not appropriate for use with the swimmer.
Further, there are conditions where a swimmer may desire to be underwater a given depth for certain intervals, such as when snorkeling. In those cases a simple water detection or delay system would not respond appropriately.